Implement some mossy blocks

This adds:
- mossy stone brick stairs
- mossy cobblestone stairs
- mossy stone brick walls

We also add another block class for walls, and while we're at it,
clean up the stairs texture function to not have a huge sprawling
elif mess for loading textures, but instead to a cheeky dictionary
lookup.

In case you're wondering, yes I am just as disgusted by this code as
you are.

overviewer_core/src/block_class.c

@@ -75,7 +75,9 @@ const mc_block_t block_class_stair[] = {
     block_purpur_stairs,
     block_prismarine_stairs,
     block_dark_prismarine_stairs,
-    block_prismarine_brick_stairs};
+    block_prismarine_brick_stairs,
+    block_mossy_cobblestone_stairs,
+    block_mossy_stone_brick_stairs};
 const size_t block_class_stair_len = COUNT_OF(block_class_stair);
 
 const mc_block_t block_class_door[] = {
@@ -132,6 +134,8 @@ const mc_block_t block_class_ancil[] = {
     block_prismarine_stairs,
     block_dark_prismarine_stairs,
     block_prismarine_brick_stairs,
+    block_mossy_cobblestone_stairs,
+    block_mossy_stone_brick_stairs,
     block_grass,
     block_flowing_water,
     block_water,
@@ -146,6 +150,7 @@ const mc_block_t block_class_ancil[] = {
     block_waterlily,
     block_nether_brick_fence,
     block_cobblestone_wall,
+    block_mossy_stone_brick_wall,
     block_double_plant,
     block_stained_glass_pane,
     block_stained_glass,
@@ -175,6 +180,8 @@ const mc_block_t block_class_alt_height[] = {
     block_prismarine_stairs,
     block_dark_prismarine_stairs,
     block_prismarine_brick_stairs,
+    block_mossy_cobblestone_stairs,
+    block_mossy_stone_brick_stairs,
     block_prismarine_slab,
     block_dark_prismarine_slab,
     block_prismarine_brick_slab,
@@ -199,3 +206,8 @@ const mc_block_t block_class_alt_height[] = {
     block_purpur_slab,
     block_wooden_slab};
 const size_t block_class_alt_height_len = COUNT_OF(block_class_alt_height);
+
+const mc_block_t block_class_wall[] = {
+    block_cobblestone_wall,
+    block_mossy_stone_brick_wall};
+const size_t block_class_wall_len = COUNT_OF(block_class_wall);

overviewer_core/src/block_class.h

@@ -46,4 +46,7 @@ extern const size_t block_class_ancil_len;
 extern const mc_block_t block_class_alt_height[];
 extern const size_t block_class_alt_height_len;
 
+extern const mc_block_t block_class_wall[];
+extern const size_t block_class_wall_len;
+
 #endif

overviewer_core/src/iterate.c

@@ -390,7 +390,7 @@ generate_pseudo_data(RenderState* state, uint16_t ancilData) {
             }
         }
         return data;
-    } else if (state->block == block_cobblestone_wall) {
+    } else if (block_class_is_subset(state->block, block_class_wall, block_class_wall_len)) {
         /* check for walls and add one bit with the type of wall (mossy or cobblestone)*/
         if (ancilData == 0x1) {
             return check_adjacent_blocks(state, x, y, z, state->block) | 0x10;

overviewer_core/src/mc_id.h

@@ -290,6 +290,9 @@ enum mc_block_id {
     block_loom = 11367,
     block_stonecutter = 11368,
     block_grindstone = 11369,
+    block_mossy_stone_brick_stairs = 11370,
+    block_mossy_cobblestone_stairs = 11371,
+    block_mossy_stone_brick_wall = 11372,
 };
 
 typedef uint16_t mc_block_t;

overviewer_core/src/overviewer.h

@@ -31,7 +31,7 @@
 
 // increment this value if you've made a change to the c extesion
 // and want to force users to rebuild
-#define OVERVIEWER_EXTENSION_VERSION 69
+#define OVERVIEWER_EXTENSION_VERSION 70
 
 #include <stdbool.h>
 #include <stdint.h>